Apparatus for making hollow articles



Oct. 12, 1943. R. w. sHoEMAKl-:R

APPARATUS FOR. MAKING HOLLOW ARTICLES 3 Sheets-Sheet l orriginl Filed March 2,;1959

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APPARATUS FOR MAKING HOLLOW ARTICLES Ori'ginal Filed March 2, 1939 3 Sheets-Sheet 2 Oct. 12, '1943. R. w, SH01-:MAKER 2,331,430

APPARATUS FOR MAKING HOLLOW ARTICLES Original Filed March 2, 1939 3 Sheets-Sheet Z5 Patented Oct. 12, 1943 APPARATUS FOR MAKING HOLLOW ARTICLES Richard W. Shoemaker, Woodbury, Conn., assignor to` Chase Brass & Copper Co. Incorporated, v Waterbury, Conn., a corporation Continuation' of applications Serial No. 259,426, March 2, 1939, and Serial No. 324,927, March 20, 1940. This application August 27, 1941, Serial 6 Claims. (Cl. 113-44) This invention relates to improvements in apparatus for making expanded hollow articles. In the speciiic embodiment illustrated, the invention relates to making branch-fittings by expanding a hollow blank by means of iiuid pressure.

cluding a pair of opposed plungers slidable in opposite directions to have an upsetting action on a hollow blank to be expanded, and provided with synchronizing means interconnecting the plungers to compel them to simultaneously have the same amount of movement toward or from one another.

Another object of this invention is to provide improved apparatus for making expanded hollow articles, including a mandrel adapted to be inserted in the hollow blank that is to have a portion expanded, the mandrel being vof a size to t the blank and being provided with groove means to transmit fluid under pressure to the portion of the blank to be expanded.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features of the said disclosure which are novel over the 'priorartf In the accompanying drawings forming part of the present disclosure, in which certain ways of carrying out'the invention are shown for illustrative purposes:

Fig. 1 is aschematic top plan View illustrating one form of apparatus for carrying out the invention;

Fig. 2 is a fragmental vertical sectional view along the line 2-2 of Fig. 1 with certain parts omitted for clearness, the rams and plungers being shown at an intermediate position of their amplitude of travel, at the start of the expanding action on the blank;

Fig. 3 is a view similar to Fig. 2 but with the apparatus shown at the completion of the expanding operation;

Fig. 4 is a transverse iragmental sectional view taken on the line 4--4 of Fig. 2;

Fig. 5 is a perspective view of the mandrel;

Fig. 6 is a front elevation partly in section of a tubular blank prior to the expanding operation;

Fig. 7 is a similar view of the blank shown in Fig. 6 after it has been completely expanded;

Fig. 8 is a view similar to Fig. 7 with the closed end of the expanded portion cut ofi?` to form the third or branch opening of a T;

Fig. 9 is a view similar to Fig. 2 of a modied form of the invention; and

Fig. 10 is a view similar to Fig. 2 of a still further modified form of the invention.-

In the description and claims, the various parts and steps are identified by specific names for convenience, but they are intended tobe as generic in their application as the prior art will permit.

Referring to the particular form of the invention illustrated in Figs. 1 to 8 of the drawings, a die or matrix 20 including front and rear halfportions 2| and 22 are adapted to be detachably connected together in any suitable Way and mounted upon the base or bed or frame of the machine 23. The die or matrix sections or portions 2| and 22 respectively have semicyclindrical die-grooves or recesses 24 and 25 (Fig. 4) which together form the cylindrical passage 26. The die sections or portions 2| and 22 also respectively have semicylindrical grooves 2l and 2B forming an expansion chamber 29 extending transversely from the die passage 26. The end of the expansion chamber 29 is closed by abutment means shown in the drawings as a pair of abutment blocks 30 and 3| respectively secured to the die portions 2| and 22 by screws 32, and

` having juxtaposed grooves in theiradjacent faces to provide an air vent 33.

A pair of hydraulic cylinders 34 and 35 respectively have ra'ms 36 and 3l which have sliding movement back and forth by means of fluid under pressure supplied to one or the other of the pipes 38, 39 on each cylinder and controlled by suitable valves (not shown) of usual form whereby the rams move back and forth under the control of an operator.

The rams 36 and 3l respectively have secured to their outer ends by means of screws 40, hollow plungers 4| and 42 respectively having interior cylindrical passages 43 and 44. The cylindrical outside surface of the plungers 4| and 42 have a close sliding iit in the cylindrical passage 26 of the die 2U, and the inside cylindrical passages 43 and 44 of the hollow plungers arcor a size to slidingly receive a mandrel 45 whicli'has a plurality of grooves 46 extending longitudinally throughout its length and arranged about its cylindrical surface to facilitate the quick free travel` of the pressure liquid lengthwise of the mandrel to the part of the blank to be expanded. regardless of the rotational and longitudinal position of the mandrel, and to aid in the pressure liquid lubricating the sliding of the blank portions along the mandrel while the mandrel supports the blank against collapsing when the blank is being upset endwise, as later more fully described. Springs 41 and 48 are respectively housed in the hollow plungers 4|, 42 and are secured to the outer ends or heads 49 and 56 of the said hollow plungers, the inner ends of the springs 41 and 48 pressing against opposite ends of the mandrel 45 and serving to position the mandrel centrally of the blank.

Fluid in the form of liquid is adapted to be supplied from a source of supply (not shown) through a pipe to a faucet or control valve 52 adapted to be opened or closed by a handle 53, the fluid then passing through a high-pressure check valve 54 and then through a pressure producing device or cylinder 55, then through a relief valve 56, then through flexible tubes 51 and 58 to connections 59 and 66 which are respectively connected to the cylindrical passages 43 and 44 of the hollow plungers 4| and 42.

The ram 36 carries a rack 6| the teeth of which mesh with the teeth of sector gears 62 and 63 respectively pivoted by means of shafts 64 and 65. The sector gears 62 and 63 respectively have cams 66 and 61 thereon.

The rams 36 and 31 respectively have L- shaped racks 68 and 69 secured to the rams by bolts 10, the racks having rack teeth meshing with the teeth of a spur gear 1| pivotally mounted at 12 on the base 23 of the machne, the racks being held in engagement with the gear 1| by backing rollers 13 and 14 pivotally mounted respectively at and 16 on the base 23 of the machine. The racks 66 and 69 and gear 1| constitute synchronizing means which interconnect the rams 36 and 31 and compel them and the plungers 4| and 42 to simultaneously have the same amount of movement toward and from one another.

When it is desired to wake an expanded hollow article, as for example a T such as 11 shown in Fig. 8, the rams 36 and 31 are caused to be moved further apart than is shown in Fig, 2, and one or both of the die portions 2|, 22 of the die are moved to separate them to permit of the transverse introduction of a tubular blank 18 and the mandrel 45 into position as shown in Fig. 2, with the mandrel 45 fitting in the interior of, and extending through the tubular blank 18 beyond each end thereof. After the die sections 2| and 22 have been closed together by any suitable means (not shown) and locked thus, the control mechanism (not shown) is actuated t0 cause the rams 36 and 31 to move inwardly toward one another to bring inner ends of the hollow plungers 4| and 42 into engagement with the ends of the tubular blank 16, and bring the springs 41 and 48 into engagement with the opposite ends of the mandrel 45 to centralize the latter. Bymeans of the handle 53, fluid under pressure, which pressure may be small such, for example, as fifty pounds per square inch, is introduced from the pipe 5| into the system to ll the pressure cylinder 55, relief valve 56, the interior of the hollow plungers 4| and 42, blank 18 and the grooves 46 of the mandrel 45, after which the control handle 53 can be turned to shut off the valve 52.

Upon proper actuation of the control mechanism (not shown) the rams 36 and 31 are caused to travel further toward one another thus causing the rack 6| and sector gear 62 to swing the cam 66 to a position to force the roller 19 and the plunger to which it is pivoted, and the piston 8| carried by the lower end of the plunger 88, downwardly against the action of the spring 82 to thus raise the fluid pressure in the system to a pressure which is suillciently high to start the expansion of the central lateral portion 83 of the blank 18 facing the expansion chamber 29 of the die 26.

At the same time that this expanding action starts to take place, the rack 6| has swung the sector gear 63 to bring a portion of the cam 61 against the roller 64 pivoted on the plunger 85 to force the plunger downwardly against the spring 86 and cause the latter to hold the valve member 81 against the valve seat 68 with sufilcient force to ensure that the pressure is raised to an adequately high amount to initiate the expansion of the portion 83 of the blank 18. If the piston 8| of the pressure cylinder 55 tends to raise the pressure too high, then the valve member 61 is raised 01T of its seat 88, permitting fluid to escape out through the escape pipe 69 of the relief valve 56. Meanwhile the rams 36 and 31 have been traveling still further toward one another and compressing the ends of the blank 18 toward one another thus feeding metal toward the location 63 of the blank 18 which is being bulged or expanded out into the expansion chamber 29.

As the portion 83 of the blank starts to expand, it quickly arrives at a point where it requires less fluid pressure to cause further expansion than was necessary to start the initial expansion, and therefore the cam 61 has a portion 90 which permits roller 84 and plunger 85 to rise and thus reduce the pressure of the plunger 85 on the spring 86, thus permitting the valve member 81 to open at a lower pressure to thus avoid risk of undue pressure damaging or bursting the portion 83 of the blank by too quick or violent expansion thereof. Meanwhile the cam portion 9| of the cam 66 has been gradually pressing the roller 19, plunger 80 and piston 8| down further to maintain the pressure in the system against loss of pressure by leakage. The pressure in excess of that required for the continued expansion of the portion 63 of the flank 18 being relieved by the relief valve 56, as previously described, the excess fluid passing outwardly through the escape-pipe 89. Thus it will be seen that once the operator starts the rams traveling toward one another, the fiuid pressure within the blank at any given instant is regulated by mechanical connections with one of the rams, so that predetermined fluid pressures are provided at predetermined positions of the travel of the ram, and without any further action by the operator, to provide various predetermined needed fluid pressures at various stages of the expansion of the blank.

Finally, when the rams 36 and 31 arrive at the positions shown in Fig. 3, the cam projections 92 and 93 respectively of the cams 66 and 61 result in a. higher pressure in the system to thus force the end 94 of the blank out sharply into the angular portions of the expansion chamber 29 to thus form the expanded or completed blank 95 (Figs. 3 and '1).

Upon causing the rams 36 and 31 to move away from one another, the fluid pressure within the completed blank 95 rapidly falls toward zero, and when the rams have moved to their original position (somewhat further apart than shown in Fig. 2) to bring the ends ofthe hollow plungers 4| and 42 out beyond the ends of the mandrel 45, the die portions 2| and 22 are opened up or separated to permit removal of the completed blank 95 (Figs. 3 and 7) with the mandrel 45. The mandrel 45 is then removed from the completed blank 95 and inserted in another blank I8 and inserted in the die sections 2| and 22,

whereupon the previously-described procedure is repeated to make another completed blank 95.

The end 94 is cut or otherwise removed from the partly-iinished blank 95 to produce the iinished T 1l shown in Fig. 8.

In the form of the invention illustrated in Fig. 9, the rams 36a and 31a respectively have secured thereto, slightly-modified forms of hollow plungers 4|a and 42a, the hollow plunger 42a having a modified form of mandrel 45a secured thereto by a screw 96. The die 20 is formed of two parts 2|, 22 similar to the construction shown in Figs. l and 2. Fluid under pressure can be brought from a suitablesource as. for example, from a, hydraulic pump or accumulator, through a pipe 5| to a control-valve 52 controlled by a handle 53, the iluid under pressure passing from the valve 52 through a check valve 54 and then to a relief valve 56, to which is secured a flexible tube 91, the other end of which is connected to the hollow plunger 4 Ia.

The rack 6| on the ram 36a aetuates the sector gear 63 having the cam 6T thereon which actuates the roller 84 of the spring-pressed plunger 85 in similar fashion to that previously described in more detail concerning Fig. 2.

The mandrel 45a is longer than the mandrel 45 used in the Fig. 2 form of the invention, and in order to avoid the need of moving the rams 36a and 31a further apart, the hollow plunger 42aY can be pivoted to the ram 31a by a screw 98, and has a rear cylindrical face 99 adapted to thrust against a corresponding cylindrical face |110 of the ram 37a. An operating-handle |0| provides for swinging the plunger 42a and mandrel 45a up away from between the die sections 2|, 22 in order to remove a completed blank and replace a new cylindrical blank thereon for another operation, after which the mandrel with the new blank is swung down to horizontal position. The die sections 2|, 22 are then closed and the expanding operation is repeated.

During the expanding operation, the pressures are controlled by the cam 61 acting on the relief valve 56 in a manner similar to that described concerning Fig. 2. Instead of a fluid medium being received under high pressure through the A ram 36h is constructed to have a greater amplitude of back-and-forth movement than any of the rams previously described, in order to provide the necessary longer working movement needed to form the blank |02 into a T, and has secured to its end a' hollow plunger 4|b having a main portion |01 slidingly fitting in the passage |03 and having a reduced portion |08 adapted to slidingly t Within the blank 102, the annular shoulder |09 being adapted to abut against the open end of the blank |02.k

' Owing to the greater amplitude of Vtravel of the ram 36h, and the consequent greater angle of rotation of the actuating cams 66a and 61a, it is necessary to have these cams displaced transversely away from the location of the rack 6|a, and therefore gears ||0 and respectively secured to shafts l2 and ||3 are located beneath and mesh with and are actuated'by the rack Gla. while the cams 66a and 61a, respectively secured on the shafts H2 and H3 at one side of the gears ||0 and I||, serve for actuating the iiuid pressure device and relief valve 56 in a manner similar to that described concerning the construction shown in Figs. 1 and 2, although the cams 66a and Bla have a greater angle of rotation than is true of the cams 66 and 61 in Fig. 2.

The fluid to provide the uid pressure to expand the blank |02 is brought in through the 'supply pipe 5|, through control valve 52 provided with control handle 53, through cheek valve 54, through the pressure device 55, through the relief valve 56, and then through the flexible tube ||l| to the longitudinal opening ||5 in the hollow plunger 4|b, from whence it enters into the interior ||6 of the blank |02.

After the system has been filled with fluid `from the supply pipe 5| and the handle 53 has been shut off, the ram 36D is caused to move to the right which causes the cams 66a and 61a to respectively actuate the mechanism of the pressure device 55 and relief valve 55 so that pipe 5|, this fluid pressure may be merely a filling i.

pressure similar to that described concerning Fig. 2, and the high pressure may be obtained by the'pressure build up due to the rams 36a and 31a moving inward and compressing the fluid within the blank and the hollow plungers 4|a.

In the form of the invention illustrated in Fig. 10, the blank to be expanded is in the Qorm of a cup or test tube |02, instead of being in the form of the tube 'I8 open at both ends. The die 20a that is to be used is formed of two parts after the expansion of the inner end of the bla-nk |02 starts, the pressure is lowered by means of the cam 61a, permitting the relief valve 56 to open at a lower pressure, and after the end has expanded to near its full position in opposite directions toward the abutments |05 and |06, then the last portion of the cam 61a to act, insures that the relief valve 56 shall only open at relatively-high pressure, and the corresponding portion of cam 66a produces a higher pressure in the pressure device 55 to thus cause the opposite end portions of the blank |02 to be pressed tightly and sharply against the abutments |05 and |06 in an analogous manner to that concerning the portion 94 described concerning Fig. 3. In the mode of operation just described concerning Fig. 10, after the expanded blank |02 is removed from die 20a, the two closed end portions of the blank that will be formed adjacent the abutments |05 and |06 are then cut oil to produce a T similar to the T '|'l shown in Fig. 8.

It will be seen that in all the forms of the invention, the pressure is changed during the upsetting or end-pushing action on a blank which is being expanded. And it will also be seen that each time the operator starts the mechanism in action to move the mandrel or mandrels in a direction to upset any one of a number of successive similar blanks, that the same pressures will be repeatedly produced at the same positions or distances of travel of the plunger or plungers panded blank.

as occurred in the action on a previously-ex- Thus, by the operator successively inserting new blanks into the mechanism and successively starting the mechanism to expand the blanks, the same pressures will automatically be reproduced at the same locations or stages of production of the successive blanks.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

l. Apparatus for making an expanded hollow article comprising: a. die having a blankreceiving passage and an expansion chamber leading therefrom; plunger means slidable in said passage and adapted to upset a hollow blank in said passage; means adapted to apply fluid under pressure to the interiorV of said hollow blank to expand a portion of the blank into said expansion chamber; and means connected with and actuated by said plunger means and constructed and arranged to vary the pressure of said fluid in said hollow blank in a predetermined way dependent upon the travel of said plunger means, said variation of iluid pressure including a rst relatively-high pressure and a later relativelylow pressure.

2. Apparatus for making an expanded hollow article comprising: a die having a blank-receiving passage and an expansion chamber leading therefrom; plunger means slidable in said passage and adapted to upset a hollow blank in said passage; means adapted to apply iiuid under pressure to the interior of said hollow blank to expand a portion of the blank into said expansion chamber; and means connected with and actuated by said plunger means and constructed and arranged to vary the pressure of said iluid in said hollow blank in a predetermined way dependent upon the travel of said plunger means, said variation of fluid pressure including a rst relatively-high pressure, a later relatively-low pressure and a still later relatively-high pressure.

3. Apparatus for making an expanded hollow article comprising: a die having a blank-receiving passage and an expansion chamber leading therefrom; plunger means slidable in said passage and adapted to upset a hollow blank in said passage; means adapted to apply fluid under pressure to the interior of said hollow blank to expand a portion of the blank into said expansion chamber; a mandrel adapted to be placed in the hollow blank and having a plurality of exterior longitudinally-extending grooves so spacedapart around the mandrel that in any rotational position of the mandrel, at least one of said grooves is adapted to transmit the fluid under pressure directly against the portion of the blank to be expanded; and means for controllably varying the pressure of said iluid at successive stages of said expanding action.

4. Apparatus for making an expanded hollow article comprising: a die having a blank-receiving passage therethrough and an expansion chamber leading from said passage; plunger means comprising a pair of plungers slidable in opposite ends of said passage and adapted to subject opposite ends of a hollow blank in said passage to upsetting action; synchronizing means interconnecting said plungers to compel them tc simultaneously have the same amount of movement toward one another; means adapted to apply iluid under pressure to the interior o! said hollow blank to expand a portion of the blank into said expansion chamber; and means connected with and actuated by said plunger means and constructed and arranged to vary the pressure of said fluid in said hollow blank in a predetermined way dependent upon the travel of said plunger means, said variation of fluid pressure including a rst relatively-high pressure and a later relatively-low pressure.

5. Apparatus for making an expanded hollow article comprising: a die having a blank-receiving passage therethrough and an expansion chamber leading from said passage; plunger means comprising a pair of fluid-actuated plungers slidable in opposite ends of said passage and adapted to subject opposite ends of a hollow blank in said passage to upsetting action: synchronizing means interconnecting said plungers to compel them to simultaneously have the same amount of movement toward one another; means adapted to apply fluid under pressure to the interior of said hollow blank to expand a portion of the blank into said expansion chamber; and means connected with and actuated by said plunger means and constructed and arranged to vary the pressure of said iluid in said hollow blank in a predetermined way dependent upon the travel of said plunger means,

said variation of fluid pressure including a ilrst relatively-high pressure and a later relativelylow pressure.

6. Apparatus for making expanded hollow articles comprising: a die having a blank-receiving passage and an expansion-chamber leading therefrom; plunger-means slidable in said passage and adapted to upset a hollow blank in said passage; means to apply fluid under pressure to the interior of said hollow blank to expand a portion of the blank into said expansion-chamber; and a mandrel adapted to be placed in the hollow blank and having its exterior provided with a plurality of longitudinally-extending grooves so spaced around the mandrel that in any rotational position of the mandrel, at least one of said grooves is adapted to transmit the uid under pressure directly against the portion of the blank to be expanded.

RICHARD W. SHOEMAKER 

